Passive and forced air cooling for fresh produce

ABSTRACT

Cases and containers for cooling produce may be cooperatively designed to provide cooling efficiencies in both passive ventilation and forced air cooling environments. Each container may include an element for helping form an opening or ventilation funnel within the center area of the cases, with a corresponding opening in the same area of the case for allowing cooling fluid to pass therethrough. Further, each container may include an element for parsing or dividing incoming forced cooling fluid into both the lid and the base. In some versions of the containers, the air may be divided based at least in part on the design of the container, including the proportions of the containers lid to base structure. In this way the forced cooling fluid may be proportionately passed into the overall container to more efficiently cool the produce therein.

BACKGROUND

The present invention relates to vented rigid plastic produce containers and the corresponding corrugated or plastic master shipping tray. More particularly, the present invention relates to a system or method of improved cooling of fresh produce held within such containers in both a passive stacked ventilation environment such as a field or cooling dock and in a horizontal forced air cooling system. In addition, the present invention also relates to the creation of a new preferred case configuration with improved synchronized venting structures, unique air flow pathways, increased pallet cube, and superior cooling.

Horticultural crops are living organisms after harvest and must remain alive and healthy until they are processed or consumed. The energy needed to stay alive comes from food reserves in the produce through a process called respiration. Heat energy is released during respiration; however, the rate of release depends on the type of produce, maturity, injuries and internal temperature. Of these factors, produce temperature has the most influence on respiration. Rapid, uniform cooling immediately after harvest to remove field and product heat helps slow respiration and provide a longer shelf life. As a rough guide, a one-hour delay in cooling reduces a product's shelf life by one day. Although this is not true for all crops, it applies to very highly perishable crops during hot weather. Lowering the temperature also reduces the rate of ethylene production and moisture loss, as well as the spread of micro-organisms and deterioration from injuries to the fruit's surface.

Berry crops, that grow in warm to hot weather, including strawberries, raspberries, blackberries, and blueberries are valuable and highly perishable commodities with a high rate of respiration. Of all these berry crops only blueberries are picked, sorted by size, and pre-cooled prior to packaging into vented rigid plastic containers of various sizes and shapes for sale. All other berry commodities are field packed directly from the plant or bush into vented rigid retail packaging that trap both field heat and product heat generated by core fruit temperature and respiration. These vented retail packages are often referred to as “clamshells” based on the nature of these containers being of a hinged middle with both a base and lid. These containers are the most widely used packaging products to deliver berry crops and other produce commodities from the field to the consumer's refrigerator; billions of containers are packed each year worldwide.

Both the box/master case and the clamshells are vented to draw out the heat of the produce post-harvest to a “7/8” ratio as fast as possible in a process known as forced air cooling to control the rate of respiration and decay of the produce. There are three main types of forced air cooling (F.A.C.) with tunnel or straight horizontal airflow systems, column vertical airflow systems, and serpentine vertical/horizontal airflow systems. Forced air cooling with tunnel or straight horizontal airflow systems are the most common with berry crops. In this system, a fan generates a vacuum either directly into a pallet or into a tunnel separating a multi pallet system. The top and the ends of the pallets are tarped to reduce short circuit air flow during the cooling process. This suction or vacuum is intended to draw out the hot or warm air from the produce and suck out all the trapped field heat, replacing it with cold air from the cooler. A “7/8” ratio is the industry standard when cooling berry crops, meaning the time needed to remove seven-eighths (87.5%) of the temperature difference between the initial temperature of produce and the temperature of the cooling medium (for forced air cooling systems, the cooling medium is refrigerated air ranging from 32-36 degrees).

The time is measured from the moment produce is first placed in the forced-air cooler to the moment it reaches the desired temperature. Achieving “7/8” cool time ensures most of the field heat and core product heat have been removed, the respiration rate of the produce has been lowered and the produce is very close to its optimum holding temperature. In theory, produce never reaches the cooling medium temperature. However, the “7/8” cooling process is intended to get produce as close as practical to the temperature of the cooling medium before release for sale.

Considering that most berry crop production is tied to warm or hot daily temperatures and long exposure to sunlight, the largest seasonal volumes will also coincide with warmest and longest days. Therefore, the greatest production of any berry crop will be tied to the late spring and early summer months of the year where production often exceeds available cooling capacity and thus increasing cooling times and respiration rates. During the peak of the season, picking and cooling times can often range from 1.5 to 4 hours per pallet creating poor conditions for fruit. Often pallets of fresh berries wait outside the cooling facility on the dock in shaded area for hours until a free spot opens up inside the cooler to start the “7/8” cooling process. In such a delayed cooling environment, ripe fruit is often left on the plant or bush and never harvested due to the high perish rate and long cooling times.

The two main components that can reduce cooling times during these peaks are the produce box/master case/returnable plastic container and the rigid plastic container. However, produce boxes are manufactured by paper converters or injection molded plastic manufacturers while the plastic rigid containers are made by manufacturers that convert rigid plastic through a process known as thermoforming. These three businesses don't work in parallel to create the best uniform cooling process, but rather have separate engineering and development groups that work within their own processes to design, engineer, and bring to market the most cost effective product with little understanding of the process as to how these components can work together as one unit to cool fruit more efficiently.

Growers often purchase their rigid packaging needs and boxes based on price, availability, and service, not based on any fundamental link between the box ventilation of one company and the clamshell design or ventilation of another company. This link could help save or capture millions of dollars each season based on improving cooling times, increased product availability, superior product quality, better shelf life, and by lowering costs.

Ventilation patterns of produce boxes/master cases and rigid plastic containers may differ greatly across the industry, but all of the commodity boxes/containers and commodity clamshells have a uniform shape and size that is of a fixed length, width, and height to accommodate predetermined packaged units of saleable fruits or vegetables at retail. Moreover, the USDA has determined that all packaged produce must be priced based on weight or cubic volume with specific regulations that are controlled and policed by a division of the USDA called Weights and Measures. Underweight packages may result in high fines, penalties, and even the suspension or termination of the grower or shippers' P.A.C.A. licenses. Some basic weights of measure for the berry industry are the 6 oz., 12 oz., 1 lb., 18 oz., 2 lb., and the 4 lb. club store packages. The USDA also states that the weight on the package must “weigh out” not only at the grower level but all the way through distribution, sale at retail, and finally on to the consumer's refrigerator.

The standardization of corrugated boxes/trays/returnable plastic containers and the internal packaging units therein (clamshells) relates to the standard produce pallet being of 48×40 inches with a specific number of boxes fitting on each layer or tie of the pallet. There are several main box configurations for the produce industry that have been developed over the last 3 decades to maximize cube, increase units per pallet spot, as well as truckload volume to reduce the impact of freight on the overall cost of produce to the consumer. Within the field packed berry category there are a number of box configurations that have become standard within the industry with the 5, 6, 8, and 12 down configurations becoming the most prevalent. The strawberry industry has a preferred 6 down corrugated box footprint with 8×1 lb. strawberry “clamshells” within, with the average retail unit dimensions of 7.0″ to 7.5″ in length, 4.7″ to 5.0″ in width, and 3.0″ to 3.50″ in height, with an average corresponding box configuration of 20 inches in length, 16 inches in width, and 3.5 to 3.75 inches in height. This configuration is known as the 6-down box configuration with 8×1 lb. strawberry “clamshells” within or the “1 lb. 6 down” configuration. In addition to the configuration of the pallet being standardized, the arrangement of the internal packaging or “clamshells” within are always identical regardless of manufacturer, as each clamshell design and shape is made for a specific box size, a unit of product weight, and unit fit into the box by number of rows and counts per row within the box.

In addition to the preferred 6 down 1 lb. strawberry configuration being the standard pallet layout, it is also the standard case unit by which most retailers purchase, set margins, track spoilage rates, track profit, monitor case turns at store level, estimate seasonal volumes, and track and process many other important retail data. For example, a major retail chain like Walmart®, with over 2,500 stores in the U.S. and Puerto, must have several produce buying groups working from one common ordering and buying platform in order to be efficient and track all relevant data with regards to perishable commodities. The inventory management and procurement platforms often notify the retail buyer daily or even hourly, in some cases, of how much product is available by case and price within their network of growers and what product is available to distribute out to stores from their regional produce warehouses. Managing this intricate system of supply and demand on perishable fresh produce is a very difficult process. In order to achieve the most fluid system of fresh produce without gapping or overloading the system with perishable product that can remain at store level longer than expected resulting in high shrink rates and spoiled product, retail buyers rely heavily on the standardization of their supply chain. Therefore, it is most advantageous for growers to follow the industry standard when making packaging decisions for their crop. Some packaging companies design and develop new corrugated footprints, such as the 9 down configuration, with new internal packaging counts of 6 or 12 instead of the standard 8 retail units, and tout various advancements in cooling, product density, and cube efficiencies only to be overlooked by the general marketplace, to a large degree, due to the considerable inertia and history with the standard 6 down configurations with 8 retail units within berry crops such as strawberries.

Therefore, it would be most advantageous to both the retailer and the berry grower if packaging companies focused their innovation efforts within the existing and accepted industry standard 6 down configuration framework or develop a new 6 down configuration as depicted within this invention that alters the dimensions and directional airflow of the system but does not change the layers on the pallet, or units within the case.

The Corrugated Box or Returnable Plastic Container (RPC)

The fundamental purpose of a corrugated box or plastic master carton is to deliver fresh fruits and or vegetables from the field to the market for purchase. There are several key factors that contribute to the overall success of its purpose:

-   -   1. The box/container provides a vehicle for stacking packages of         product or whole produce from the field in an organized,         stacked, and protected shipping format.     -   2. The box/container provides the initial horizontal ventilation         structure and air flow method for cooling the fruit or         vegetables inside it. How these venting structures are cut and         line up with the clamshell containers or whole produce inside is         the most critical function of the box when attempting to cool         the product in the most efficient and uniform method.     -   3. The box provides a transfer of air flow from the cooler into         the rigid plastic containers within to cool the held fruit. It         must also draw or transfer the air flow to the next         box/container on the horizontal pallet to continue the process.     -   4. Air transfer within the box/container may include both         vertical and horizontal air flow or transfer vents that could         assist in an even and uniform cooling process. It is critical to         review both directional air flows to maximize stacked         ventilation and create the most effective method of cooling.

It is also critical to discuss the manufacturing and forming of the corrugated master tray or “produce box” when reviewing how the box will perform in conjunction with the held retail rigid plastic, “clamshell,” units within. The manufacturing process begins with varying grades of container boards which are represented as “the medium” (the fluted middle layer) and “the linerboard” (the flat facings of the board). These two types of board not only differ in function and purpose but also are made from different types of trees as well. After the liner and the medium are combined by use of a cornstarch based adhesive to form a single faced web in a single facer machine, the web enters a double gluer machine and double backer machine that bonds the liner to the single web creating the completed board. The corrugate board is then slit and scored to the specifications required as well as continues to the cut off knife where it is cut to the specific dimensions of the requested board. The sheets are then stacked and prepared for shipment to the converting plants.

There are two main types of converting machines, the rotary die cutter and flexo folder gluer machine. Both play a role in adapting sheets of corrugate into produce boxes including printing designs and branding, cutting to proper dimensions, folding and gluing corners, and flaps and side walls. This last step has the greatest potential for variance with regards to the final formed tray. Unlike rigid plastic containers that are thermoformed by a single and exact mold and matching trim press, the corrugated box uses hot melt glue in between folded corners and flaps to hold its shape and dimensions. The variance in internal dimensions is critical as even a slight variance ranging from ⅛ to 1/64 of an inch on each corner of the tray may create a loose fitting internal packaging arrangement of “clamshells” and thus create a failed air circuit in between clamshells within the case. Failed air circuits are the leading cause of air flow passing through the case without penetrating the ventilation structures of “clamshells” and thus increasing cooling times and decreasing efficiencies.

After the sheet is converted into a box it is again stacked, palletized and readied for shipment to the grower, or a packaging company that will do the final assembly for the grower. It is here at final assembly where printed and branded corrugated boxes receive the addition of stacked sets of empty rigid plastic containers. After the corrugated boxes are filled with the predetermined size and number of “clamshells”, the entire package is ready to be shipped to the field for packing.

The Rigid Plastic Vented Produce Container or “Clamshell”

The fundamental purpose of a “clamshell” (or “punnet”) is to deliver a specific weight or measure of fruits and or vegetables from the field to the market for sale. There are several key factors that contribute to the overall success of its purpose:

“Clamshells” provide a uniform packing unit with a weight specific size which makes it possible to pack, cool, ship, merchandise and sell at retail. Clamshells provide an extra layer of protection for fruit and or vegetables from the field to the market and are an improvement over pulp open trays or injection molded open top baskets.

Clamshells utilize clear plastic to help identify the product quality and ripeness of fruit to consumers. Most designs include: ribbing or smooth wall structures that ensure the package will stack at retail, a secure closure lock that holds the container together both before and after opening and reclosing multiple times, a ventilation pattern designed to cool fruit within, and a label platform for brand or grower identification. These are the main contributing factors that make it the method of choice for the produce industry today.

The most overlooked attribute of the clamshell is its ability to cool the fruit effectively and uniformly to reduce produce respiration rates and increase the product's shelf life. With California being the largest berry growing state in the United States, berries are often picked, cooled, and then shipped all the way across the country for sale. Therefore, the greater the shelf life, the greater market opportunity for the grower.

All these attributes are critical to the functionality and performance of these containers; however, for over 25 years, the standard thermoformed clamshell design for all fruit or vegetable crops utilizes a tapered wall both on the lid and the base of the container which has proven to create a failed airflow circuit within the box/master case/RPC container. The tapered nature of the thermoformed clamshells can't be changed as the draft angle helps to form the parts, stack the parts together during transit, and enables the parts to be de-nested for labeling application. All these features and functions of the container makes it possible to manufacture a light weight and inexpensive package as not to burden the consumer with expensive packaging on food items.

There is also a greater gap or “V channel” in-between the clamshells as the draft angle is increased, so the taller the clamshell the greater the failed circuit of air becomes which affects cooling times and increasing product respiration rates. The “V channel” is the space in between each row of clamshells and it is commonly referred to as a “V” channel, though the true shape of the channel is an inverted V-shape. This inverted v-shaped channel will be referred to hereinafter as the “V” channel.

The greater the draft angle on the side walls the greater the gap in between the “clamshells.” In addition, the longer the row of containers the larger the failed air circuit. The average clamshell has an overall base height of 2.75-3.00 inches with a draft angle of 8-10 degrees, creating a 35-50% failed circuit within the box. These failed circuits occur when cold air is pulled inside the box/container and bypasses the hot fruit or vegetable inside the “clamshell” by taking the path of least resistance through the “V channels” and thus following the vacuum or suction back out of the box/container. The “V channels” in-between the clamshells on both the top and the bottom of the clamshells will always be the path of least resistance regardless of the shape, location, and size of the two-dimensional side vents within the corrugated box or RPC. In addition to the “V” channels created on the outside of the packages, there also exists some “clamshell” designs with bottom pathways or concaved air flow channels. These pathways or concaved channels do offer some additional ventilation into the bottom of the package, however, they also provide a larger center failed air circuit, or open circuit within the case, as most of the airflow rushes past the 90-degree ventilation apertures without a significant pull or draw extending up and into the center of the package. An example of this can be seen in U.S. Pat. No. 8,424,701. The “tunnel vent” or bottom “V” channel creates a larger than necessary bottom opening, or open circuit, that greatly reduces the efficiencies of a closed or non-connected bottom ventilation ramp or bridge.

Combined System—Produce Box/RPC and Internal Rigid Parts

The corrugated box or RPC must work together with the internal packaging to create a total system of air flow, cooling, and respiration control. If one or more of the properties are not aligned together and thus not working as a complete system, the end result will most likely be a failure (a short circuit of air flow) which can lead to an increase in cooling times and poor quality of fresh produce. Considering that the draft angle of all clamshells is a fundamental design feature but also a fundamental design flaw when cooling fruit or vegetables inside a box with forced air cooling, the “V channels” must be blocked or air must be redirected away from them to close the failed circuit and direct air into the clamshell's vents to cool the fruit and vegetables inside.

Assuming the “V channels” in-between the clamshells can be blocked either by the design of the corrugated paper or plastic master shipping case or by a secondary component added to the master case, a unique venting structure and pattern thereof must still be designed into the rigid plastic container to harness the newly directed airflow to create the most effective cooling method or process possible within the combined system. Most of the current ventilation patterns within rigid plastic containers on the market today use a straight down punch method that creates a punch, hole, or side wall vent at the base of a tapered or chamfered ribbed structure. By the nature of these ribbed structures and the current punch and die system used to create them, the ventilation patterns run along a horizontal plane around the perimeter of the container both on its base and lid; however, this pattern or system of ventilation creates no directional airflow or draw into the clamshell itself. Most of the airflow surrounding the container simply bypasses the outer perimeter front facing venting structures by taking the least path of resistance and therefore creating a failed air circuit which produces little actual cooling of fresh produce inside the container. Containers that don't rely on any number of side wall ventilation apertures but rather on a system of linking the box air flow directly into the container through a large side air vent with a concaved base channel, also have challenges with failed air circuits present in the surrounding “clamshells” due to case dimensional variances during case erecting, as well as the failed air circuit present within the base concaved channel or pathway. Additionally, the loss of side ventilation apertures in the corners of the container can create hot spots and form condensation against side walls, both prior to and after the cooling process, and therefore subject produce to increased respiration rates over time.

As each produce box or returnable plastic container manufacturer touts their own unique ventilation pattern and the benefits or advantages therein so does each rigid plastic manufacturer. However, since the mid 1990's, both the University of California Davis and the University of Ontario Canada have concluded that the number of and size of vents have little overall effect on reducing both cooling times and respiration rates. An increase in vent size and number of vents on rigid containers simply don't equate into faster cooling times and may increase cooling times. Most manufacturers of rigid plastic containers, as well as growers alike, ignore these studies and follow the disproved theory that more vents are better when designing and developing air flow systems. The underlining problem that exists with vacuum cooling is that air will take the path of least resistance when pulled through the box or master case so simply increasing the vent size and number of vents on rigid parts does little to do with increasing cooling times. If the air is not directed into the path of the vent structures, or if the vent structures themselves are two dimensional in nature causing air to flow past along a straight edge or line, the main underlining problem of the failed air circuit remains. Moreover, the current two-dimensional front facing venting structures are often blocked by denser fruit such as small strawberries, blackberries, raspberries, and most notably blueberries, causing little to no airflow being pulled from container to container. This problem causes fruit within rigid retail packages to be cooled from the outside in as the temperature of passing air slowly cools air and fruit within the container; therefore, a container that specifically directs airflow to penetrate the container at all layers of fruit and especially in between layers of fruit is key to have unobstructed airflow and cool fruit faster.

In greater detail, the overall misconception that more ventilation is better is compounded by the false perception that cooling from the outside of the package inward, or in some cases from the bottom of the clamshell upward, is the most effective method of cooling produce within. In most cases a dual method of cooling, from the inside out, and from the outside in, and at all layers of fruit would be the most efficient method of rapidly and evenly cooling produce within rigid plastic containers, however, there isn't a rigid retail unit, “clamshell” or punnet on the market today that has these features incorporated into one design in combination with the master shipper box or RPC.

The only two clamshell designs that do utilize an air tunnel, channel, or pathway system to allow air to reach the center or bottom of the container are the system highlighted in U.S. Pat. No. 8,424,701 and the system highlighted in U.S. Pat. No. 6,644,494. Both systems use an air flow channel or channels by which to allow air to enter or pull from the bottom of the container. These tunnels or channels also have two-dimensional venting structures which are often located at the top or near top of tunnel structures at 90-degree angles from the air flow. It is very important to note that a 90-degree ventilation aperture at the top of a channel is very inefficient and a poor method of penetrating the bottom of the container, simple put there is no line of sight for air to penetrate the container and instead must draw from radical 90-degree vents to accomplish vertical cooling. In addition, as air travels at a high velocity, it fills all the available space within the tunnel or channel and will bypass the ventilation apertures located at the top 10% of the tunnel.

Moreover, the system venting structures and the relationships between the interior and exterior packaging (the “clamshells”, and boxes or RPCs), must function in both a passive stacked ventilation environment and within a forced air cooling system. Considering most current box and “clamshell” packaging solutions take little to no account of the two varying stages of cooling, (1) field passive ventilation, and (2) forced air cooling, it is advantageous to develop a combined package that performs under all conditions, especially considering that the passive ventilation environment may persist for several hours until the forced air process can begin.

Passive Ventilation

Passive ventilation is the most overlooked of the two cooling stages. As the pallet of fruit or vegetables is being built at the field level, the Law of Convection needs to be considered to maximize the release of heat from the semi-closed pallet system. By understanding the Law of Convection, a system of interlocking both box and “clamshell” vents may be created to draw hot air up and out of the pallet and replace it with cooler air from the sides of the pallet.

Convection is the transfer of internal energy into or out of an object by the physical movement of a surrounding fluid that transfers the internal energy. Although the heat is initially transferred between the object and the fluid by conduction, the bulk transfer of energy comes from the motion of the fluid. Convection can arise spontaneously (or naturally or freely) through the creation of convection cells or can be forced by propelling the fluid across the object or by the object through the fluid. In our particular case the “fluid” is represented by air molecules surrounding the fruit or vegetable inside the rigid plastic container, “clamshell,” as well as air molecules surrounding the internal rigid packaging within the box or RPC.

To create turbulence within the pallet and to a greater extent within the vented rigid container to generate movement of hot air upward, vertical pathways or funnels must be created as well as an overall strategy of how to capitalize on the creation of low pressure within the pallet when hot air rises to continually create upward and inward movement of air. Stack ventilation uses temperature differences to move air without the presence of wind. Hot air rises because it expands and is less dense than air around it. Therefore, by designing a complete pallet system (box and clamshell) that takes into account stack ventilation and by understanding Bernoulli's Principle, a unique pallet structure can be built to maximize passive ventilation (the rising of hot air in a semi closed system). In Bernoulli's Principle, “cool air is sucked in through low inlet openings as hotter air escapes through high outlet openings. The ventilation rate is proportional to the area of the openings. Placing openings at the bottom and top of an open space will encourage natural ventilation through the stacked effect.” Hot or warm air will exhaust through the top layer of the pallet, resulting in cooler air being pulled into the pallet from the outside through openings at the bottom or sides. Openings at the top, side, and bottom should be roughly the same size to encourage even air flow through the vertical space.

Forced Air Cooling

The process of Forced Air Cooling can range from 1 to 3 hours depending on the power of the fan, fan size, number of pallets being cooled, initial temperature of fruit, air flow pathways within boxes and corresponding venting patterns within internal packaging, density of fruit, and the desired temperature at 7/8 ratio. When creating a strategy for the most efficient and uniform cooling process to use with Forced Air Cooling, the number of internal packages across the cooling web and the depth or number of clamshells within each box layer must be considered to ensure the least possible opportunities for a failed air circuit to develop within the pallet. For example, a box with an internal packaging lay out of 2 across and 4 deep has a greater chance of creating a failed air circuit than a box that has a clamshell layout 4 wide and only 2 deep across. In this particular example, the primary reason why a shorter width or depth box design is more efficient and less likely to cause a failed air circuit is due to reduced distance and reduced number of clamshells that air needs to travel through horizontally before getting repositioned into the next box, and so on.

Furthermore, the most efficient way to cool produce within internal rigid packages, “clamshells”, would be to force the air to travel inside the containers and not around it. In order to accomplish this goal, each box vent must have a corresponding internal packaging vent with no gap existing between the two. Ideally each “clamshell” would have an extended vent area that would be inserted directly into the box vent and force a straight pass through of air from one side of the box to the other passing though the internal packaging and or directed air flow.

Directed airflow is the key to unlocking faster cooling times, and by having an extended vent area that can split airflow within the corrugated walls of the box into multiple pathways is critical in dividing directable air flows into the container at varying levels of fruit height. For example, by splitting the airflow within the corrugated wall of the box by an 80/20 ratio in the master vent, air can be directed to the proportional amount of fruit weight by area—80% base and 20% lid. The ratio of split is directly related to the size of the container and its corresponding parts (base and lid). The larger the lid of the container, the greater the increased ratio of the lid airflow vent being split, this is due to the fact that a larger lid will also accommodate a larger percentage of fruit that lies above the main basket line, or gap vent in between the base and lid. Conversely a container with a shallow or flat lid will have a very minimal directional airflow split within the corrugated walls as a larger majority of fruit will be held within the base of the container.

Current clamshell packaging and box configurations do not split airflows within the corrugated walls of master cases but rather have a large opening vent that distributes air randomly between the lid and base and the air generally flows to the least path of resistance and not into the containers.

The present invention solves all of the above stated problems within the preferred 6 down configuration of the 8-1 lb. strawberry unit tray as well as identifies unique embodiments and features in both the produce tray and the clamshell in doing so.

DESCRIPTION OF RELATED ART

U.S. Pat. Nos. 6,007,854, 6,644,494, 7,413,094, 8,083,085 and 8,424,701 disclose various types of packaging and cooling systems designed to improve cooling of fresh produce. None of these references disclose a passive air flow system linking box funnels with gaps within internal rigid packaging, a central box vent corresponding to split airflows within the corrugated case wall directing air to a main vent and a lid vent area, and lastly none offer a five-tiered venting system (1. bottom ramp vent, 2. bottom side wall vent, 3. mid-range vent, 4. main gap vent, and 5. side wall lid vent) within the rigid packaging to maximize both passive ventilation and forced air cooling.

SUMMARY OF INVENTION

This section provides a general summary of the disclosure and one or more of its advantages and is not a comprehensive disclosure of the full scope of all the features, of all the alternatives or embodiments or of all the advantages. Additionally, specific featured embodiments are not limited to examples given below and may be transferred to new packaging shapes, sizes, and weight designations depending on the intended or required solution.

The Corrugated Box/RPC

To better understand the disclosed invention and how the new corrugated configuration influences cooling efficiencies, it is best to outline and compare the differences between the old style and the new configuration. The old style 6 down configuration utilizes a rough box dimension of 20 inches in length, 16 inches in width and 3.5 inches in height with 2 rows of 4 deep clamshells within, and a 3 by 2 (6 total) box tie on a pallet in the cooling direction of 48 inches on the pallet. This configuration allows for an initial cooling exposure of 2 clamshells per box, 3 boxes wide, or 6 clamshells in total across the cooling web. The new corrugated configuration utilizes a rough box dimension of 24 inches in length, 13.3 inches in width, and 3.50 inches in height with 4 rows of 2 deep clamshells within, and a 2 by 3 (6 total) box tie on the pallet in the cooling direction of 48 inches on the pallet. This configuration allows for an initial cooling exposure of 4 clamshells per box, 2 boxes wide, or 8 clamshells in total across the cooling web. Thus increasing the cooling web by 25% which greatly effects the number of containers immediately exposed to the coldest air during the forced air process (from 6 to 8).

Newton's Law of Cooling states that the rate of temperature of a body is proportional to the difference between the temperature of the body and that of the surrounding medium, as well as, the cooling of an object results from energy flow from the body to its surroundings. It is also relevant to understand how there exists an exponential decline of the cooling temperature of the surrounding medium as it is pulled through the box and exposed to the energy flow from various new bodies (hot fruit). Therefore, it is exponentially more efficient to cool 8 units at 6 deep across a cooling web than 6 units at 8 deep. The farther the frigid air travels across hot fruit the lesser its effect of cooling are, as its own temperature rises due to the transfer of energy and heat.

To understand this more completely, the following example is given. As the cooling medium, air, travels over the body (hot produce held within a “clamshell”), it will inevitably decline in cooling effectiveness as its own temperature is increased as the body (hot produce) transfers its energy (heat) to the surrounding medium (air) making it less effective over each “clamshell” unit across the depth direction of the web. Therefore, it is most advantageous to pull the cooling medium (air) across the greatest number of initial units in a row with the least number of subsequent units behind it. A further detailed analysis shows that this new configuration pulls air across 8 pounds of initial hot produce with only 6 pounds of subsequent depth across the cooling web at a relevant starting temperature ranging between 32-36 degrees in the forced air cooling environment versus the old configuration which pulls air across only 6 pounds of initial hot produce with a larger subsequent 8 pounds remaining across the web. As previously noted, this new box configuration increases the number of “clamshell” units being cooled across the web from 6 to 8, or an increase of 25% with the added benefit of a reduction in the exponential decline of the cooling medium. Moreover, this new configuration with its new internal dimensions are also relevant to the development of alternative “clamshell” shapes and sizes that can be beneficial within a stacked ventilation cooling environment. The new shapes and sizes may also be specifically designed to limit cube within the container to help reduce over packing of weight units. Current clamshell designs range from 10-30% of overpacked fruit within each container which also increases the cooling times as overpacking fruit means more fruit weight to cool that the grower is not being compensated for by consumers.

Internal Rigid Packaging “Clamshell”

The new configuration allows many new “clamshell” shapes and sizes across many produce commodities, but for the purpose of this explanation and comparison the one-pound standard strawberry “clamshell” will be further explained. Within the new box configuration, the standard one pound rectangular “clamshell” is altered to almost a square design of roughly 6.13″ in length, 5.63″ in width and 3.25-3.50″ in height with rounded corners. The rounded corners on each clamshell come together when placed into the box to form a rounded semi 4-pointed star shape located 3 across the center of the length direction of the box or RPC. When these rounded semi-star shaped openings are linked to a hole or cut out in the box or RPC directly beneath it there exists 3 center air funnels that extend unobstructed from the base of the pallet to the top within each case or box layer. These funnels are extremely advantageous in a passive stacked ventilation environment as the rising less dense hot air has a direct path up and out of the pallet. Each box will have 3 unobstructed stacked funnels linked together with a total of 18 funnels per pallet layer creating the largest opportunity for hot air to rise within the pallet without degrading the construction and functionality of the pallet. Additional funnel vents may be added to the box on each corner and each half semi-round pointed star at the edges of each clamshell if desired.

In addition to the unobstructed funnel vents that line the bottom of the case, there are 16 minor vent funnels in each box (2 per “clamshell” space) that are directly linked to ventilation holes in the base of the “clamshell.” These vent funnels may be attached to special ramps within the clamshell with vent apertures or similar vent apertures may be recessed into the box to help hot air escape up and out of the pallet through the various funnels.

In this one-pound standard strawberry case and “clamshell” example, there are a total of 19 funnel vents (3 large unobstructed center case vents and 16 minor vents) specifically designed to encourage natural passive ventilation through the stacked effect. Hot or warm air will exhaust up through the funnel vents and out through the top layer of the pallet, resulting in cooler air being pulled into the pallet from the outside through the openings at the bottom or sides of the pallet. Considering cool air will be entering the pallet from the sides, it is critical that the “clamshell” is directly linked into the side of the box to enhance the natural cooling effect of stacked ventilation. This link between the box and clamshell is accomplished by means of an extended vent area on the clamshell that inserts into a larger area of the box thus linking the two directly as one complete vent.

To summarize all the disclosed embodiments or features, herein is a rigid plastic container (clamshell, tub, or punett with lid) and a master case which may include any combination of the below disclosed features resulting in improved airflow within the combined set, with particular significance pertaining to the removal of hot field air or product heat within, during both passive ventilation and forced air cooling processes: BOX or MASTER CASE (a) any number, shape, location, or size of unobstructed vertical funnel vents to create a natural convection effect within the pallet, (b) any number, shape, location or size of a main horizontal air flow transfer vent with interlocking rigid plastic container features designed to link the box directly to the container within to reduce failed air circuits and split airflows within the corrugated walls and within the combined set, (c) any number, shape, location, or size of minor vertical funnel vents located beneath rigid plastic containers to create a natural convection effect within the pallet; RIGID PLASTIC CONTAINER (a) any number, shape, location, or size of a three dimensional front or side facing venting structure on the outer wall of the base of the container that is open on one or more sides, (b) any number, shape, location, or size of a two or three dimensional front or side facing venting structure on the inner walls of a tunnel, channel, or pathway arrangement running through the bottom or base of the rigid part in whole or in part, (c) any number, shape, location, or size of a three dimensional front or side facing venting structure on the outer wall of the lid portion of the container that is open on one or more sides walls, (d) any shape, wave, curve, or internal ribbed feature present inside the three dimensional venting structure that directs air flow within the rigid part, (e) any special shape or form present within the three dimensional venting structure located on the non-vented portion of the walled structure that aids in directing air flow in and out of the container, (f) any special shape or form present within the three dimensional venting structure located on the non-vented portion of the walled structure that aids in the creation of air turbulence within the rigid part, (g) any number of tunnels, channels, ridges, or pathways and corresponding vented apertures in the base of the container that allows the vacuum cooling process to reach the front, center, and back portions of the container, (h) any number, shape, location, or size of a singular or multiple opening or cut within the tunnel, channel, ridge or pathway that pulls air from the container during the cooling process utilizing a ramp style method of pulling air from the container and reducing the angle from which air travels in and out of the container, (i) any three dimensional vented structure, or cut on an angle which faces the desired direction of the vacuum to pull air from within the container reducing the potential of a failed circuit within the combined set, (j) any space, shape, cone, circle, ring, ramp, or tunnel like structure in the base of the container designed to circulate or transfer cold air into the base of the container, (k) any style, shape, size, or location of a series of vents within the tunnel, channel, ridge, or pathway structure that forces air up and into the container, (1) any style, shape, size, or location of a series of mid-range venting structures located within the rigid side walls to create open pathways of air transfer in between layers of fruit, (m) any style, shape, size, or location of a main air transfer vent with interlocking case features to create a direct pathway from outside the case to inside the rigid container reducing the possibility of a failed air circuit, (n) any style, shape, size, or location of a series of venting structures located within the lid of the container that correspond to the minor funnel vents located within the master shipping case to create pathways for air to exhaust up and out of the container's lid, (o) any style, shape, size, or location of a lid bridge with vent apertures designed to both strengthen the lid structure and provide ventilation or air transfer in the lid that link to minor air funnels located either directly above or adjacent to the bridge structure on the base of the master shipping case, (p) any style, shape, size or location of indented pathways or channels with venting apertures within the base of the rigid plastic container that are flush with a raised lid bridge with venting apertures on the lid while identical containers are stacked at retail, and (q) and style, shape, size, or location of an extended vent that separates the airflow with the corrugated wall of the master box by percentage of air needed to cool fruit by weight location within the base and lid of the container.

All of these features or embodiments will differ from container configuration, size and shape of container, layers of fruit intended within each container, weight distribution of fruit between the base and lid, and commodity intended for each container, but all will be similar in nature to the above embodiments described in the MASTER CASE (a-c) and the RIGID PLASTIC CONTAINER (a-q) listed above. In addition, the features and embodiments may also differ in size, shape, number, length and width, three-dimensional shape, angle or cut of vents to match the directional air flow intended within the box.

BRIEF DESCRIPTION OF THE DRAWINGS

While the specification concludes with claims which particularly point out and distinctly claim the invention, it is believed the present invention will be better understood from the following description of certain examples taken in conjunction with the accompanying drawings, in which like reference numerals identify the same elements and in which:

FIG. 1 is an isometric of the invention depicting both hot and cold air flow.

FIG. 2 is an isometric view perspective view of the present invention depicting the base only with particular attention to the channel/pathway and venting structure within.

FIG. 3 is an isometric view of a three-dimensional air vent depicting open vents on 2 sides of the ribbed structure and a directional air feature on the non-vented or non-cut wall.

FIG. 4 is an isometric view of a combination air channel/pathway combined with a three-dimensional air vent at both the front and back of the pathway and two ramp style channel vents.

FIG. 5 is an isometric view of a channel or pathway with 8 ramp style vents along the base, as well as, a close up view of the ramp style vent.

FIG. 6 is an isometric view of a dual ramp style pathway vent.

FIG. 7 is an isometric view of several preferred embodiments depicted within a rigid retail container.

FIG. 8 is an alternative isometric view of several preferred embodiments within a rigid retail container.

FIG. 9 is of 2 top down views of rigid retail containers with differing bottom preferred embodiments.

FIG. 10 is a similar view of a rigid retail container in FIG. 9 with a different preferred embodiment on the lid structure.

FIG. 11 is a diagram depicting how the rigid retail units may be stacked both within the master case and on the retail shelf.

FIG. 12 is an isometric view of a master shipping case with its corresponding rigid retail unit configuration.

FIG. 13 is of two differing isometric views of the same master shipping container and its corresponding retail found in FIG. 12.

FIG. 14 is a top down view of a pallet in the preferred embodiment configuration.

FIG. 15 is an isometric view of the pallet configuration in FIG. 12.

FIG. 16 is an isometric view of a corrugated vent pattern and “clamshell” vent structures within.

FIG. 17 is a similar isometric view of FIG. 16 with an alternative corrugated vent pattern that is specific to the internal packaging vents.

FIG. 18 is an identical isometric view of FIG. 16 with the percentage vent split between the lid vents and the main vents identified for reference.

FIG. 19 is an isometric view of a cross section where the rigid plastic container extends into the corrugated wall and divides the airflow into separate pathways (main vent 80% and lid vent 20%).

FIG. 20 is an isometric view of a cross section depicting the lower corrugated vent and the aligning rigid plastic vents including the mid-range vent, bottom side vent, and the bottom ramp vent.

FIG. 21 is an isometric view of a cross section of the case depicting how 2 rigid containers interlock and the airflow pathways on the lower level of the container.

FIG. 22 is an isometric view similar to FIG. 21 depicting the lowest airflow pathway and the flow through the case vent into the case beneath to complete the circuit.

FIG. 23 is an isometric view of the front panel of the rigid container and a close up of the ramp vent depicting the two angled side vents at 30 degrees.

FIG. 24 is an isometric view of the new preferred six down case with clamshells depicting the funnel vent pathway and hot air escaping the case during a passive stacked environment.

The drawings are not intended to be limiting in any way, and it is contemplated that various embodiments of the invention may be carried out in a variety of other ways, including those not necessarily depicted in the drawings. The accompanying drawings incorporated in and forming a part of the specification illustrate several aspects of the present invention, and together with the description serve to explain the principles of the invention; it being understood, however, that this invention is not limited to the precise arrangements shown.

DETAILED DESCRIPTION

The following description of certain examples of the invention should not be used to limit the scope of the present invention. Other examples, features, aspects, embodiments, and advantages of the invention will become apparent to those skilled in the art from the following description, which is by way of illustration, one of the best modes contemplated for carrying out the invention. As will be realized, the invention is capable of other different and obvious aspects, all without departing from the invention. Accordingly, the drawings and descriptions should be regarded as illustrative in nature and not restrictive.

It will be appreciated that any one or more of the teachings, expressions, versions, examples, etc. described herein may be combined with any one or more of the other teachings, expressions, versions, examples, etc. that are described herein. The following-described teachings, expressions, versions, examples, etc. should therefore not be viewed in isolation relative to each other. Various suitable ways in which the teachings herein may be combined will be readily apparent to those of ordinary skill in the art in view of the teachings herein. Such modifications and variations are intended to be included within the scope of the claims.

FIG. 1 shows the front and side view of a rigid retail unit and use of three-dimensional side vents (10) with two open side vents directed into the path of the vacuum. Dark arrows, indicated by the hot air flow (20) being pulled from the rigid container via the three-dimensional side vent structure (10) and cold air flow (30) entering the container from alternative suction points along the width direction of the container.

FIG. 2 shows how the pathway or channel at base of clamshell (40) running along the base of the container can be formed by raising the base of the container off the box floor with a series of corner blocks or feet at base of clamshell (50). The drawing also shows how two oblong vent structures at front of ramp vents (60) at either end of the channel can be cut into the side wall of the container thus creating a pathway to reach the channel or pathway within. In addition, this drawing shows the use of two alternating ramp style vents (70) adjacent to the center pathway to pull air at alternating points within the container and therefore causing turbulence from within the container.

FIG. 3 shows a detailed view of two three-dimensional side vent structures (10) side by side, with two open side wall cuts on adjacent side walls (100) of a ribbed feature (110) and a third smooth indented wall feature (120) on the non-vented structure to push or guide airflow into the container as the forces of the vacuum draw directly into the vent. A ribbed indented wall feature (90) is provided as illustrated.

FIG. 4 shows a detailed side view of a center pathway or channel at base of clamshell (40) combined with two large three dimensional side vents (10) located at the beginning and ending of the pathway or channel at base of clamshell (40). The pathway or channel at base of clamshell (40) draws air from the center of the container by use of two center ramp style vents (70) while the two large three dimensional side vents (10) pull air from the outside of the container. This combined effect creates a two directional flow air, both outside in and inside out at the same time, causing turbulence inside the container rarely reached by conventional venting of one method or another. Additionally, smooth side walls (100) as well as the use of ribbed features (110) create the three-dimensional side venting structures (10). Two directional ramp style vents (70) are used in the center of pathway or channel at base of clamshell (40) to create the most effective penetration of the air into the container as the air follows up the ramp of the first style vent (70) penetrating the container and then exists down the second ramp style vent (70) on the backside.

FIG. 5 depicts the base of a rigid retail package with 8 ramp style vents (70) running in a two by four parallel down the center of the pathway or channel at base of clamshell (40) with curved walls, creating a smooth transition on base of container (180) into the pathway or channel at base of clamshell (40) to protect soft fruit from rough edges or hard transitions. This system of using directional ramp style vents (70) inside of a pathway or channel at base of clamshell (40) may be utilized if the directional air flow of the vacuum can be predictable and reliable. If the directional air flow changes from one direction to the other depending on which way the box is positioned on the pallet layer, then a dual sided ramp vent, not pictured, must be used as not to block the path of the incoming vacuum along the base of the pathway or channel at base of clamshell (40).

FIG. 6 is of a close-up of a dual directional ramp style three-dimensional vent structure, (200). These dual directional ramp vent structures (200) may be placed anywhere on the base of the container where air is directed to draw air from or into the container. The dual sloping ramp vent base feature (160) is far superior to that of a simple round or circular vent positioned at the top of a channel or pathway because the angle is not as steep and creates a smooth transitional draw of air into the container. Air flows into the container through the ramp vent aperture (140) transitions up into the container and then back out down the dual directional ramp vent (200). This feature is especially advantageous while air is traveling at a high rate of speed.

FIG. 7 is an isometric view of a rigid plastic retail unit, “clamshell,” with preferred embodiments which are advantageous to the increased cooling of fresh produce within. These preferred embodiments are part of a five-tiered system of ventilation, (Top Vent, Master Side Vent, Mid-Range Vent, Bottom Side Vent, and Base Vent/Ramp Vent) that provide cooling effects in both a passive stacked ventilation environment and in a forced air cooling system. The container (80) has both top external lid vents (230) as well as internal lid vents (240) on the label and stacking platform. These top side vents are particularly advantageous to cool fruit in a vertical stacked system as well as reduce the amount of condensation present on the lid. The main clamshell vent (210) with its extended main vent lip (220) locks into the master case to provide both a source of cooler airflow within a stacked ventilation system, as well as, a forced air cooling source linked directly from outside of the pallet into each clamshell within the cooling web. The mid-range vent (250) allows for air circulation in between layers of packed fruit. This unique mid-range vent breaks up the side walls (100) or the ribbed feature (110) allowing for both the vertical air flow in a passive stacked ventilation system, as well as, the horizontal air flow in a forced air cooling environment. It is critical to have both directional airflows at this key range of product heat to best ventilate each stacked layer of fruit along the walls of the container. The bottom side vents (260) are positioned at the base of the container to allow for both vertical and horizontal airflow. The pathway or channel at base of clamshell (40) creates space for the base or bottom tier of vents, not pictured. This bottom tiered vent system links to the minor funnel vents located within the master shipping case to maximize the rise of hot air up the pallet in-between the pallet layers.

FIG. 8 shows an alternative isometric view found in FIG. 7—the bottom side view. Positioned within the pathway or channel at base of clamshell (40) is the preferred embodiment bottom ramp vent two-dimensional (270). The ramp or tunnel and corresponding bottom vent allows for a near center ventilation of the base layer of fruit without creating a failed air circuit within the shipping case, as previously noted with a continuous tunnel or pathway. Airflow is pulled from the bottom layer of fruit by the forced air cooling environment with 100% of the air drawing up from the closed tunnel or ramp vent system. Any combination, number, or shape of bottom ramp vent two-dimensional (270) in combination with the minor funnel vents within the master case, may be created to maximize the airflow from the bottom of the container and within the case.

FIG. 9 is a top down view of the preferred embodiments found in FIG. 7, and FIG. 8 with an alternative indented vent aperture (280). The indented vent aperture (280) differs from the tunnel or ramp vent system in that the vent aperture extends into cut outs within the master case while the ramp vent aperture (140) is raised off the master case floor. The indented aperture rests just above the lid area of the lower clamshell in the stacked pallet layer, this creates a unique pulling of air in-between pallet layers creating a larger passive stacked effect of air rising throughout the system. Air will rise or be pulled from the surrounding side vent, mid-range vent, and master vent along the cooling web to both draw hot air up and out of the pallet. Additionally, the indented vent aperture (280) may be more advantageous with soft fruit as the indented aperture is not raised and does not come in contact with fruit but yet provides adequate lower ventilation.

FIG. 10 is of both a top down view and an isometric view of the preferred embodiments found in FIG. 7, and FIG. 8 with the addition of a lid bridge vent (290). The center bridge vent or possible multiple bridge vents across a lid platform, not pictured, are advantageous when combined with the bottom indented vent aperture (280) especially on larger pack sizes such as a 2 lb, 3 lb, and 4 lb container. Traditionally these larger containers have large label platforms with little to no ventilation causing condensation and trapping of hot air within the stacked ventilation environment. The lid bridge vent (290) corresponds in height to the depth of the indented vent aperture (280) allowing for the even stacking or layering of clamshells at retail with the combined continued ventilation of both systems. The combination of the raised bridge vent and the inverted base vent also provide a greater rigidity to the light weight rigid container allowing for greater number of stacked containers without risk of lid failure or collapse that may result in the toppling of the container stack on retail shelves, especially with heavier containers. Furthermore, the raised bridge vent may also be combined with a raised bridge or tunnel on the base separating the container into compartments. The raised vented compartments walls may also have side vents that correspond in size and number to that on the raised bridge to increase airflow within the separate compartments. Non-uniform venting patterns and structures within both the raised compartment bridge or tunnel and the raised lid bridge may also be advantageous depending on the commodity of fresh produce and the size and shape of each compartment, not pictured.

FIG. 11 is an example of how the raised lid bridge vent (290) and the lower indented vent aperture (280) might be positioned both within the stacked at case (310) with the corrugated tray layer in between (300) and the stacked at retail shelf (320) once removed from a master shipper case.

FIG. 12 is an isometric view of the preferred master shipping case (330) and the preferred clamshell arrangement or rigid retail unit configuration (350) as well as, the primary vertical master vent slots location (340). In this particular example, the preferred new master case configuration is a two by three layer across the cooling web of 48″ long by 40″ deep. The preferred internal clamshell arrangement (350) is four containers long and two containers deep within each case. The vertical master vent slots (340) are present on both sides of the case creating a straight airflow system that exists within the clamshell. Air flow is repositioned every two units as it passes through three trays during the forced air cooling process.

FIG. 13 is of both an isometric view and a top down view of the master shipping case (330) highlighting both the master funnel vents (360) and vertical minor funnel vents (370). In this example of the preferred master shipping case (330) there are three master funnel vents (360) and sixteen minor funnel vents (370). The master funnel vents (360) are aligned to gaps in-between the clamshell arrangement. This is best depicted in the top down perspective in which the major funnel vents can be seen through the rounded corners in-between the clamshell arrangement. Both the master funnel vents (360) and minor funnel vents (370) are designed to maximize the amount of hot air escaping out the top of the pallet while cooler air is drawn into the pallets through the master vent slots (340) during the passive stacked ventilation cooling process.

FIG. 14 is a top view of a master pallet configuration (380) with 18 master funnel vents (360) present within the pallet layer. A typical pallet layer configuration with a box height of 3.50 inches, would consist of twenty to twenty-two cases high or 360 to 396 master funnel vents within the total pallet configuration. This massive increase in air flow during the passive stacked cooling environment greatly improves air flow within the system both while the pallet is being built in the field and while it waits on a cooling dock.

FIG. 15 is an isometric view of a pallet configuration of the preferred embodiment pallet configuration (390) with an internal clamshell arrangement (350) four long and two deep within each case across the cooling web. This figure best shows how cold air will travel across the cooling web through the master vent slots (340) on the master shipping case (330) during the forced air cooling process. It also is particularly visible that the air will be repositioned every two units in width as the cold air is pulled by a vacuum from one side of the pallet to the other through three master shipping cases. This diagram also depicts how eight units might be cooled at one time across the cooling web versus the current 1 lb. strawberry unit of six units, not pictured. Cooling a larger number of units across the web, as well as, repositioning airflow over a shorter number of units within each case is the most efficient use of cold air while cooling fresh produce in a horizontal forced air cooling environment.

FIG. 16 is an isometric view of the side panel of the master corrugated box (300) and retail container unit, “clamshell” (80) held within. In the main vent view the drawing clearly shows the main vent (210) the extended lip (220) that locks the retail unit (80) into the box (300) and splits the air flow pathways. This unique interlocking feature serves a dual purpose in securing the container to the box to limit failed air circuits but also slits the air flow pathway into the main vent and the lid vent located directly above (230). The lid vent (230) pictured here is a slot or side wall vent punch on the lid, but it may also be advantages for future designs to have a horizontal vent located directly above the extended lip and on the wall of the lid, not pictured. The lower case vent (400) clearly exposes both mid-range vents (250) and the lower ramp vent apertures (270). The lower-case vent (400) provides a direct line of sight of the bottom air flow pathways into the retail container, “clamshell”, and thus limit the percentage of failed circuit airflow on the lower portion of the container. In addition, these multiple ventilation pathways allow cool air to penetrate the fruit within the container at varying depths and layers of fruit. This system provides the most allowable air flow pathways into the container and fruit within, while limited the potential failed circuit pathways. Considering that hot air will rise and transfer heat from lower levels to top layers of fruit it is critical to remove heat from container/fruit at varying layers to decrease heat or energy transfer.

FIG. 17 is an isometric view similar to FIG. 16 with an alternative bottom corrugated vent shape (410). The alternative corrugated vent is to show how the size and shape of the vent may be altered to increase access to the various retail container unit ventilation while limiting failed air circuits. The shape and size of the vent may be contoured to match any number of vents along the side wall of the container including but not limited to the mid-range vents (250) the side wall bottom vent (not pictured), or the ramp vent (270).

FIG. 18 is the identical isometric view of FIG. 16 with the percentage of internal corrugated wall air flow pathway division explained by percentages depicted by an air flow area (420) and an air flow area (430). The ability to lock the retail container unit within the corrugated wall and split the airflow ratio within its structure is unique in the field and represents an enormous leap in the cooling process. Considering that fruit within the retail container unit is held within both the lid and the base of the container and that fruit may block some of the main vent due to fruit size, shape or position within the container it is most advantageous to split the airflow pathway in relation to the percentage of fruit that may be positioned above the base basket line and held in the lid. In this illustrated example of the present invention, the retail container unit has a height of 3.25 inches with a split between the base and the lid structure of roughly 80/20. Therefore, by splitting the airflow within the corrugated wall at the same ratio it is certain that the proportional amount of airflow will be distributed within the clamshell. As illustrated in FIG. 18, the air flow is split into two portions, with the first portion being 80% of the incoming air, depicted as air flow area (420) and with the second portion being 20% of the incoming air, depicted as air flow area (430). This system of airflow diversification also helps to ensure that there are no hot spots in the corners of the containers or areas for condensation to build. It is important to be able to adjust the percentages of the air flow pathway split to match the amount of fruit that may be held or not held within the lid portion of the container. If by design the container has a taller lid to encompass more fruit capacity while the base remains the same then the ratio must be altered to reflect the amount of fruit expected to be held within the lid area. For example, if a similar container needed an expanded lid to hold larger fruit sizes and the ratio of base to lid is altered to 70/30 two things would be required (1) a taller box would be needed to hold the larger container, and (2) a larger main side wall vent to match the new larger dimensions and the new ratio of base to lid. Conversely is the lid is reduced to hold a lesser amount of fruit capacity than the opposite adjustments would be required (1) a smaller box to hold the decreased container size, and (2) a reduced main side wall vent to match the smaller dimensions and the new ratio of base to lid.

FIG. 19 is a cross section of the master box and the retail container unit at the intersection of the air flow pathways in the corrugated wall and the air flow pathways directional flow into the retail container unit. The cross section of the master case wall (440) provides a clear visual of the extended main vent lip (220) that not only locks the retail unit into the master corrugated box but also splits the airflow pathway in the desired percentage based on the container base and lid dimensions and the expected fruit held within. Extended main vent lip (220) is comprised of an upper lip (221) primarily responsible for dividing the air flowing into container (80) and lower lip (222) primarily responsible for locking container (80) with master shipping case (330).

In the present example, the main air flow pathway (450) flows directly into the container at 80% of the corrugated opening, while the lid air flow pathway (460) flows towards the lid vent apertures (230) at 20% of the corrugated opening. This ratio is determined by the placement of upper lip (221) relative to the size of main clamshell vent (210) and the size of container (80) and may be adjusted along with other features of container (80) to reach the desired ratio of air flowing into the lid and base of container (80).

As cooling fluid is forced into master vent slot (340) of master shipping case (330), a first potion of the fluid is directed toward along lid vent airflow path (450) and into lid vent apertures (230). Similarly, as fluid is forced into master vent slot (340), a second portion of the fluid is directed along main vent air flow pathway (450) and into main clamshell vent (210). In some versions of the present container (80), the structural component responsible for dividing the forced fluid is upper lip (221) of extended main vent lip (220). As shown in FIG. 19, upper lip (221) may be angled to ramp or “cam” the inflowing fluid upwardly toward external lid vents (230) and ultimately into the lid portion of container (80). Inasmuch as the inflowing cooling fluid is divided into two portions, fluid also flows below upper lip (221) and into main clamshell vent (210) to cool the base portion of container (80).

FIG. 20 is the exact isometric view of FIG. 19 with illustrations identifying the lower ventilation air flow pathways. The three lower air flow pathways are identified as: the mid-range air flow pathway (470) the bottom side wall airflow pathway (480) and the ramp vent air flow pathway (490) each air flow pathway travels into the retail container unit through the corresponding vent opening, mid-range aperture (250), side wall vent aperture (260), and the bottom ramp aperture (140). It is critical to not only have a multiple of bottom airflow pathways as differing locations and sizes during the forced air cooling process to quickly expel heat from the container as fast as possible but also during the passive stacked air cooling process. As hot air is expelled up an out of the pallet through the master funnel vents cooler air will flow into from the sides through the identified lower aperture vents outlined above.

FIG. 21 is an isometric view of a cross section of the width direction of the master case encompassing two interlocked retail container units. The units are locked into one another and locked into the corrugated case walls. The illustration is depicting the airflow pathways of the mid-range (470) and the ramp aperture (490). The multilayered air flow pathways are depicted how they would travel through the interlocking retail container units within the case. It is critical not only to lock the containers to the corrugated box but also interlock them together to create the best possible air flow transfer during the forced air cooling process.

FIG. 22 is an identical isometric view of FIG. 21 but highlights the lowest air flow pathway in the case (500). The bottom-most pathway doesn't penetrate the retail container unit but rather travels through the ramp vent and down into the case beneath it through a minor funnel vent opening, and into the lid of the retail container unit beneath. It is critical to allow some air flow to be unrestricted in order to keep the air flow moving throughout the system. Directing an air flow pathway into the center portion of the lid of the case beneath is also a great way to create elevate trapped heat in the center of the lid area. The jump of air is minor to the overall airflow pathway and is intentionally limited as to not create a large center failed air circuit like in the previously stated examples of tunnels that are present at the bottom of container and found in U.S. Pat. Nos. 6,644,494 and 8,424,701.

FIG. 23 is of an isometric view of the ramp vent (70) and aperture (140) plus a close-up view of the same. Unlike any other current tunnel vent listed in prior art these aperture vents are not straight down punches but are at a 30-degree angle, and therefore providing a clear line of sight from the vent location to the air flow pathway. This is particularly advantageous as the ramp (70) is lowered at a lesser degree to the bottom of the corrugated case and thus forces most of the airflow pathway to pull up and into the retail container unit through the ramp aperture (140) as the ramp narrows. These two bottom apertures (140) are critical to providing an air flow pathway to the center part of the retail unit without creating a large failed air circuit. An enlarged view of ramp aperture (140) is depicted as element (510).

FIG. 24 is an isometric view of the new preferred six down case (300) with 8 retail container units (80), round funnel vents in the case (360), star shaped funnel vents (530), in between the intersecting retail container units (80), and the corresponding and hot air escaping the case (520) during a passive stacked environment. Considering during the peak of the season it may takes hours before a pallet of fresh fruit can reach the forced air coolers, it is most advantageous to have a pallet system that allows hot air to continually escape the pallet and thus reducing the core temperature of the pallet prior to forced air cooling. The specific rounded corners of the retail container unit (80) allow for the creating of the star shaped funnel vent (530) when grouped together within the case. It is not advantageous enough to have vents on the bottom of the case at random. Each corrugated bottom vent (360) must correspond with a matching container funnel vent (530) to create an unobstructed pathway up and out of the pallet. Unobstructed hot air rises faster and creates a larger energy force leading to the evacuation of center pallet core heat with the addition of cooler air being pulled in from the sides of the pallet causing a natural convection effect to cool the pallet before the forced air cooling process.

EXEMPLARY COMBINATIONS

The following examples relate to various non-exhaustive ways in which the teachings herein may be combined or applied. It should be understood that the following examples are not intended to restrict the coverage of any claims that may be presented at any time in this application or in subsequent filings of this application. No disclaimer is intended. The following examples are being provided for nothing more than merely illustrative purposes. It is contemplated that the various teachings herein may be arranged and applied in numerous other ways. It is also contemplated that some variations may omit certain features referred to in the below examples. Therefore, none of the aspects or features referred to below should be deemed critical unless otherwise explicitly indicated as such at a later date by the inventors or by a successor in interest to the inventors. If any claims are presented in this application or in subsequent filings related to this application that include additional features beyond those referred to below, those additional features shall not be presumed to have been added for any reason relating to patentability.

Example 1

A cooling system for produce comprising: a case comprising a wall, a master vent slot defined by the wall and configured to pass a fluid therethrough; and a container configured to be received in the case in a cooling position and configured receive the fluid passed through the master vent slot, the container comprising a base, a lid, wherein the lid includes a lip, a main clamshell vent defined between the lid and the base and configured to fluidly communicate with the master vent slot when the container is disposed in the base in the cooling position, wherein the lip is positioned to direct a portion of the fluid passing through the master vent slot away from the main clamshell vent when the container is disposed in the base in the cooling position.

Example 2

The cooling systems or methods of Example 1 or any of the subsequent Examples, wherein the master vent slot includes a master vent slot size, wherein the lip is positioned based at least in part on the master vent slot size.

Example 3

The cooling systems or methods of any of the previous or subsequent Examples, wherein the main clamshell vent includes a main clamshell vent size, wherein the lip is positioned based at least in part on the main clamshell vent size.

Example 4

The cooling systems or methods of any of the previous or subsequent Examples, wherein the lid includes a lid height, wherein the base includes a base height, wherein the lip is positioned based at least in part on the lid height and the base height.

Example 5

The cooling systems or methods of any of the previous or subsequent Examples, wherein the lid includes a side wall and a lid vent defined in the sidewall, wherein the lip is positioned to direct the portion toward the lid vent.

Example 6

The cooling systems or methods of any of the previous or subsequent Examples, wherein the lip extends into the master vent slot when the container is disposed in the base in the cooling position.

Example 7

A cooling system for produce comprising: a set of containers, each container comprising: a base, wherein the base includes two opposed sidewalls, two opposed end walls, and a bottom wall; a lid, wherein the lid includes two opposed sidewalls, two opposed end walls, and a top wall; an end recess, wherein the end recess includes an end portion recessed into one of the end walls of the base and a bottom portion recessed into the bottom wall of the base; a side recess, wherein the side recess is recessed into one of the side walls of the base; a first mid-range vent defined by one of the end walls of the base and disposed in the end portion of the end recess; a second mid-range vent defined by one of the sidewalls of the base and disposed in the side recess; a bottom ramp vent defined by the bottom wall of the base and disposed in the bottom portion of the end recess; and a case, wherein the case includes two opposed sidewalls, two opposed end walls, and a bottom wall, wherein the case is configured to receive the set of containers therein, the case comprising: a plurality of master vent slots defined by each end wall of the case; and a plurality of funnel vents defined by the bottom wall of the case.

Example 8

The cooling systems or methods of any of the previous or subsequent Examples, wherein the case further comprises an imaginary longitudinal center line extending along the center of the bottom wall of the case from one end wall to the other end wall, wherein the plurality of funnel vents includes a set of master funnel vents disposed along the imaginary longitudinal center line.

Example 9

The cooling systems or methods of any of the previous or subsequent Examples, wherein the plurality of funnel vents includes a set of minor funnel vents disposed on both sides of the imaginary longitudinal center line.

Example 10

The cooling systems or methods of any of the previous or subsequent Examples, wherein a group of four containers in the set of containers define an opening therebetween, wherein the opening is in fluid communication with at least one of the master funnel vents when the group of four containers is disposed in the case.

Example 11

The cooling systems or methods of any of the previous or subsequent Examples, wherein the set of containers is a set of eight containers, wherein the case is sized to receive the eight containers in two rows and four columns therein with three openings defined therebetween, wherein the set of master funnel vents comprises three master funnel vents disposed whereby each funnel vent is in fluid communication with an opposing one of the three openings.

Example 12

The cooling systems or methods of any of the previous or subsequent Examples, wherein each container is a clamshell container, each container further comprising a hinge, wherein the lid is connected to the base via the hinge.

Example 13

A method comprising: disposing a first container, a second container, a third container, and a fourth container in a case, wherein the first container, the second container, the third container, and the fourth container define an opening therebetween; aligning a master funnel vent defined by a bottom wall of the case with the opening, wherein the master funnel vent and the opening are in fluid communication; defining a pair of first main clamshell vents between a lid of the first container and a base of the first container; defining a pair of second main clamshell vents between a lid of the second container and a base of the second container; and aligning a pair of master vent slots defined by a pair of sidewalls of the case with the pair of first main clamshell vents and the pair of second main clam shell vents, wherein the pair of master vent slots, the pair of first main clamshell vents, and the pair of second main clamshell vents are in fluid communication.

Example 14

The cooling systems or methods of any of the previous or subsequent Examples, further comprising forcing fluid into one of the pair of master vent slots, through the pair of first main clamshell vents, through the pair of second main clamshell vents, and out the other one of the pair of master vent slots.

Example 15

The cooling systems or methods of any of the previous or subsequent Examples, further comprising forming a bottom ramp vent in a bottom wall of the base of the first container.

Example 16

The cooling systems or methods of any of the previous or subsequent Examples, further comprising aligning a minor vent slot defined by a bottom wall of the case with the bottom ramp vent, wherein the minor vent slot and bottom ramp vent are in fluid communication.

Example 17

The cooling systems or methods of any of the previous or subsequent Examples, further comprising forming a mid-range vent in an end wall of the base of the first container.

Example 18

The cooling systems or methods of any of the previous or subsequent Examples, wherein the bottom ramp vent is disposed in a recessed portion of the bottom wall of the base of the first container.

Example 19

The cooling systems or methods of any of the previous or subsequent Examples, wherein the mid-range vent is disposed in a recessed portion of the end wall of the base of the first container.

Example 20

The cooling systems or methods of any of the previous or subsequent Examples, wherein the recessed portion of the bottom wall and the recessed portion of the end wall are contiguous.

Example 21

A method of cooling produce, the method comprising: filling a set of four containers with produce; disposing the set of four containers in a case, wherein the set of four containers are disposed in the same general plane in a two by two configuration; allowing fluid to passively rise via convection from below the case to above the case through a master funnel vent defined by a bottom wall of the case and an opening defined between the set of four containers; and in response to the fluid passively rising through the master funnel vent, drawing heat out of the set of four containers through a plurality of vents defined therein to entrain the heat in the passively rising fluid.

Example 22

The cooling systems or methods of any of the previous or subsequent Examples, further comprising: defining a first master slot in a first sidewall of the case, wherein the first sidewall extends from the bottom wall; defining a second master slot in a second sidewall of the case, wherein the second sidewall extends from the bottom wall, wherein the first sidewall and the second sidewall are parallel; and forcing fluid into the first master slot, wherein the fluid forced into the first master slot passes through a first container in the set of four containers and a second container in the set of four containers and out the second master slot.

Example 23

The cooling systems or methods of any of the previous or subsequent Examples, further comprising orienting the first container and the second container within the case to dispose a first main clamshell vent of the first container proximate the first master slot, a second main clamshell vent of the first container proximate a first main clamshell vent of the second container, and a second main clamshell vent of the second container proximate the second master slot.

Example 24

The cooling systems or methods of any of the previous or subsequent Examples, further comprising: forming a bottom recessed portion in a bottom wall of a base of the first container, wherein the bottom recessed portion is recessed inwardly toward an interior of the first container; and venting the interior of the first container through a bottom ramp vent defined by the bottom wall of the base and within the bottom recessed portion.

Example 25

The cooling systems or methods of any of the previous or subsequent Examples, further comprising: forming an end recessed portion in a side wall of the base of the first container, wherein the end recessed portion is recessed inwardly toward the interior of the first container; and venting the interior of the first container through a mid-range vent defined by the end wall of the base and within the end recessed portion, wherein the bottom recessed portion and the end recessed portion are contiguous.

Example 26

The cooling systems or methods of any of the previous or subsequent Examples, further comprising: inserting a portion of a first container in the set of four containers into a master vent slot defined by a sidewall of the case, wherein the sidewall extends from the bottom wall; forcing fluid into the master vent slot toward the first container; dividing the forced fluid into a first portion and a second portion; receiving the first portion of the forced fluid in a lid vent defined by a lid of the first container; and receiving the second portion of the forced fluid in a main clamshell vent defined by the lid and a base of the first container.

Example 27

The cooling systems or methods of any of the previous or subsequent Examples, wherein the first portion and the second portion are based on a size of the master vent slot and a size of main clamshell vent.

Example 28

A method of cooling produce, the method comprising: forcing a fluid through a case toward a container disposed within the case; and directing a first portion of the fluid through a lid of the container; and directing a second portion of the fluid into a main clamshell vent defined between the lid and a base of the container.

Example 29

The cooling systems or methods of any of the previous or subsequent Examples, further comprising directing the first portion through the lid of the container via an element of the container.

Example 30

The cooling systems or methods of any of the previous or subsequent Examples, further comprising directing the second portion through the main clamshell vent via the element.

Example 31

The cooling systems or methods of any of the previous Examples, wherein the element is an angled lip. 

What is claimed is:
 1. A cooling system for produce comprising: (a) a case comprising: (i) a wall; (ii) a master vent slot defined by the wall and configured to pass a fluid therethrough; and (b) a container configured to be received in the case in a cooling position and configured receive the fluid passed through the master vent slot, the container comprising: (i) a base; (ii) a lid, wherein the lid includes a lip; (iii) a main clamshell vent defined between the lid and the base and configured to fluidly communicate with the master vent slot when the container is disposed in the base in the cooling position, wherein the lip is positioned to direct a portion of the fluid passing through the master vent slot away from the main clamshell vent when the container is disposed in the base in the cooling position.
 2. The cooling system of claim 1, wherein the master vent slot includes a master vent slot size, wherein the lip is positioned based at least in part on the master vent slot size.
 3. The cooling system of claim 1, wherein the main clamshell vent includes a main clamshell vent size, wherein the lip is positioned based at least in part on the main clamshell vent size.
 4. The cooling system of claim 1, wherein the lid includes a lid height, wherein the base includes a base height, wherein the lip is positioned based at least in part on the lid height and the base height.
 5. The cooling system of claim 1, wherein the lid includes a side wall and a lid vent defined in the sidewall, wherein the lip is positioned to direct the portion toward the lid vent.
 6. The cooling system of claim 1, wherein the lip extends into the master vent slot when the container is disposed in the base in the cooling position.
 7. A cooling system for produce comprising: (a) a set of containers, each container comprising: (i) a base, wherein the base includes two opposed sidewalls, two opposed end walls, and a bottom wall; (ii) a lid, wherein the lid includes two opposed sidewalls, two opposed end walls, and a top wall; (iii) an end recess, wherein the end recess includes an end portion recessed into one of the end walls of the base and a bottom portion recessed into the bottom wall of the base; (iv) a side recess, wherein the side recess is recessed into one of the side walls of the base; (v) a first mid-range vent defined by one of the end walls of the base and disposed in the end portion of the end recess; (vi) a second mid-range vent defined by one of the sidewalls of the base and disposed in the side recess; (vii) a bottom ramp vent defined by the bottom wall of the base and disposed in the bottom portion of the end recess; and (b) a case, wherein the case includes two opposed sidewalls, two opposed end walls, and a bottom wall, wherein the case is configured to receive the set of containers therein, the case comprising: (i) a plurality of master vent slots defined by each end wall of the case; and (ii) a plurality of funnel vents defined by the bottom wall of the case.
 8. The cooling system of claim 7, wherein the case further comprises an imaginary longitudinal center line extending along the center of the bottom wall of the case from one end wall to the other end wall, wherein the plurality of funnel vents includes a set of master funnel vents disposed along the imaginary longitudinal center line.
 9. The cooling system of claim 8, wherein the plurality of funnel vents includes a set of minor funnel vents disposed on both sides of the imaginary longitudinal center line.
 10. The cooling system of claim 9, wherein a group of four containers in the set of containers define an opening therebetween, wherein the opening is in fluid communication with at least one of the master funnel vents when the group of four containers is disposed in the case.
 11. The cooling system of claim 10, wherein the set of containers is a set of eight containers, wherein the case is sized to receive the eight containers in two rows and four columns therein with three openings defined therebetween, wherein the set of master funnel vents comprises three master funnel vents disposed whereby each funnel vent is in fluid communication with an opposing one of the three openings.
 12. The cooling system of claim 7, wherein each container is a clamshell container, each container further comprising a hinge, wherein the lid is connected to the base via the hinge.
 13. A method comprising: (a) disposing a first container, a second container, a third container, and a fourth container in a case, wherein the first container, the second container, the third container, and the fourth container define an opening therebetween; (b) aligning a master funnel vent defined by a bottom wall of the case with the opening, wherein the master funnel vent and the opening are in fluid communication; (c) defining a pair of first main clamshell vents between a lid of the first container and a base of the first container; (d) defining a pair of second main clamshell vents between a lid of the second container and a base of the second container; and (e) aligning a pair of master vent slots defined by a pair of sidewalls of the case with the pair of first main clamshell vents and the pair of second main clam shell vents, wherein the pair of master vent slots, the pair of first main clamshell vents, and the pair of second main clamshell vents are in fluid communication.
 14. The method of claim 13, further comprising forcing fluid into one of the pair of master vent slots, through the pair of first main clamshell vents, through the pair of second main clamshell vents, and out the other one of the pair of master vent slots.
 15. The method of claim 13, further comprising forming a bottom ramp vent in a bottom wall of the base of the first container.
 16. The method of claim 15, further comprising aligning a minor vent slot defined by a bottom wall of the case with the bottom ramp vent, wherein the minor vent slot and bottom ramp vent are in fluid communication.
 17. The method of claim 16, further comprising forming a mid-range vent in an end wall of the base of the first container.
 18. The method of claim 17, wherein the bottom ramp vent is disposed in a recessed portion of the bottom wall of the base of the first container.
 19. The method of claim 18, wherein the mid-range vent is disposed in a recessed portion of the end wall of the base of the first container.
 20. The method of claim 19, wherein the recessed portion of the bottom wall and the recessed portion of the end wall are contiguous.
 21. A method of cooling produce, the method comprising: (a) filling a set of four containers with produce; (b) disposing the set of four containers in a case, wherein the set of four containers are disposed in the same general plane in a two by two configuration; (c) allowing fluid to passively rise via convection from below the case to above the case through a master funnel vent defined by a bottom wall of the case and an opening defined between the set of four containers; and (d) in response to the fluid passively rising through the master funnel vent, drawing heat out of the set of four containers through a plurality of vents defined therein to entrain the heat in the passively rising fluid.
 22. The method of claim 21, further comprising: (a) defining a first master slot in a first sidewall of the case, wherein the first sidewall extends from the bottom wall; (b) defining a second master slot in a second sidewall of the case, wherein the second sidewall extends from the bottom wall, wherein the first sidewall and the second sidewall are parallel; and (c) forcing fluid into the first master slot, wherein the fluid forced into the first master slot passes through a first container in the set of four containers and a second container in the set of four containers and out the second master slot.
 23. The method of claim 22, further comprising orienting the first container and the second container within the case to dispose a first main clamshell vent of the first container proximate the first master slot, a second main clamshell vent of the first container proximate a first main clamshell vent of the second container, and a second main clamshell vent of the second container proximate the second master slot.
 24. The method of 23, further comprising: (a) forming a bottom recessed portion in a bottom wall of a base of the first container, wherein the bottom recessed portion is recessed inwardly toward an interior of the first container; and (b) venting the interior of the first container through a bottom ramp vent defined by the bottom wall of the base and within the bottom recessed portion.
 25. The method of 24, further comprising: (a) forming an end recessed portion in a side wall of the base of the first container, wherein the end recessed portion is recessed inwardly toward the interior of the first container; and (b) venting the interior of the first container through a mid-range vent defined by the end wall of the base and within the end recessed portion, wherein the bottom recessed portion and the end recessed portion are contiguous.
 26. The method of claim 21, further comprising: (a) inserting a portion of a first container in the set of four containers into a master vent slot defined by a sidewall of the case, wherein the sidewall extends from the bottom wall; (b) forcing fluid into the master vent slot toward the first container; (c) dividing the forced fluid into a first portion and a second portion; (d) receiving the first portion of the forced fluid in a lid vent defined by a lid of the first container; and (e) receiving the second portion of the forced fluid in a main clamshell vent defined by the lid and a base of the first container.
 27. The method of claim 26, wherein the first portion and the second portion are based on a size of the master vent slot and a size of main clamshell vent.
 28. A method of cooling produce, the method comprising: (a) forcing a fluid through a case toward a container disposed within the case; and (b) directing a first portion of the fluid through a lid of the container; and (c) directing a second portion of the fluid into a main clamshell vent defined between the lid and a base of the container.
 29. The method of claim 28, further comprising directing the first portion through the lid of the container via an element of the container.
 30. The method of claim 29, further comprising directing the second portion through the main clamshell vent via the element.
 31. The method of claim 30, wherein the element is an angled lip. 